The Finer Points of Finishing: Part 2

Once the clear sap has boiled the day away and whittled away into an inch of golden goodness in the bottom of the boiling pan, it’s time to drain it into one of our big canning pots.  Thankfully there’s a handy-dandy spigot in the corner to make the job easier.  After our most recent 12-14 hour boils, we’ve drained out about four gallons of near-syrup at this stage.  Then it’s off to the turkey fryer to boil off the last gallon of water.  The ring of the fryer burner is a perfect fit for our canning pots, and the propane burner is much easier to control.  Also perfect for roasting hot dogs, if a person needs a little protein to balance out the sugar.  Plus, it keeps us from making a mess of the kitchen stove.  On the burner, the syrup gently boils for quite a while with little attention, but when it gets close to finished, watch out!  That baby can boil over in a heartbeat.  Sadly, we know this from experience.

The syrup is officially finished when it reaches the magical 66% sugar content, or boils at seven degrees above the boiling temperature for water.  In most cases that would be the expected 219 degrees, unless the barometric pressure is all wonky.  For those of you who have been following the April weather in Minnesota this year, we think you’d agree there may have been some barometric wonkiness.  So rather than rely on a thermometer, we let our hydrometer tell us when it’s quittin’ time.  The hydrometer measures the density of the syrup, to give us a more precise measure of the sugar content.  We dip our handled hydrometer cup into the hot syrup and let the hydrometer float gently inside.  When the red line is visible above the syrup line in the cup, we call it a day.  And thank our lucky stars we avoided another sticky syrup spillover.

The Finer Points of Finishing, Part 1

So after five or so hours of boiling, our 40 gallons of sap has magically turned into a gallon of syrup, right?  Oh, if only.  To “finish” the syrup to the proper 66% sugar content in the pan would be to risk overshooting the evaporation and scorching the syrup.  Thus rendering the syrup inedible, and leaving the evaporator operator sobbing in the corner of the sugar shack in the fetal position.  Nobody wants to see that.  So the trickiest part of the entire syrup operation might be deciding when to pull the pan off the wood stove and transfer the near-syrup to a large pot to be finished over a more controlled heat source.  Pull the pan off too early, and we waste lots of time boiling off water we could have boiled in the more efficient flat pan.  Pull it off too late and, yup, we’ll be playing “Taps” for our fallen batch of syrup.

Maple Sap Streaming into the Boiling Pan

Since we’ve engaged in a couple of 12+ hour, 180 gallon boiling marathons this season, we’ve faced an even more difficult decision:  when to quit feeding the fire at the end of the night?  Once the last of the sap has left the barrel and streamed into the pan, there’s still quite a bit of boiling to do.  So rather than staying up another two hours to feed the fire and pull off the pan to cool, we stop stoking the fire and let the residual heat of the stove and the sap do a little more evaporating before morning, when we'll fire up the finishing operation.  As you might imagine, estimating how much evaporating happens while we’re sleeping is like estimating how long our kids' good mood will last after the maple syrup sugar rush wears off.  In other words, nearly impossible.  We nearly lost our first batch this way – we woke up to nearly-finished syrup in our pan, just a smidgen away from scorched syrup.  Thankfully, we were still a few points away from the magic 66% sugar content for finished syrup, so we didn’t lose any of our sweet amber goodness.  Sweet dreams, indeed! 

Boil, Baby, Boil!

First of all, we want to be clear.  Even though this incredibly long stretch of cold weather has extended our season and will give us our biggest syrup haul ever, we still want spring to arrive NOW just as much as anyone else in Minnesota!  We’re willing to call it quits on sap collection.  We’re ready for warmer weather.  Any day now, thanks!

Sap Delivery & Preheating Mechanism

But in the meantime, when the world gives us sap, we make syrup!  No matter how cold it gets inside, it’s toasty warm inside the Sugar Shack.  To keep the sap at a rolling boil, we add wood to the stove every 10-12 minutes.  We use a mix of oak and maple.  Nope, not for a smoky flavor, but because our oak is drier and contains more BTUs so it burns hotter, while the maple is wetter and burns longer.  This keeps the fire burning at 750 to 800 degrees Fahrenheit, as measured by the thermometer mounted on our smokestack.  The thermometer has an ominous name; “burn indicator” is stamped on the bottom of it.   Boil, baby boil… syrup inferno!  No, no infernos, please – that’s why we have a panel of cement board mounted between the stove and the back wall, and a fire extinguisher mounted prominently near the door of our Sugar Shack.  Safety first, syrup second! 

To make sure the syrup keeps boiling steadily as we add more sap to the pan, we use copper tubing to carry the sap from our 55 gallon drums into the pan.  The tubing has a valve like our house’s plumbing, where we can adjust the speed of the sap flow.  And the copper wraps around the smokestack twice, so that the sap is already preheated a bit by the time it goes streaming into the pan.  During the height of the boil, we try to adjust the flow to keep about 3 inches of boiling liquid in the pan for optimal evaporation.  With this setup, we can boil the excess water off 50 gallons of sap in about 6 hours.  Or about fifty rounds of adding wood to the fire.  Not that we're counting.

Quicker Collection

See that beautiful photo there?  That nearly full bucket of fresh, begging-to-be-boiled sap?  Yes, that’s what we’ve been waiting for.  The sap run is at its peak, and we aim to collect every available drop. A couple of years ago, the bottleneck of our syrup operation was the boiling.  We solved (or partially solved) that issue by upgrading our stove.   

So now our bottleneck is sap collection.  The 55 gallon plastic drum bungee corded onto a wagon (aka the “collection cart”), towed by our four wheeler just isn’t giving us the efficiency we’re looking for.  There’s still the stopping & dismounting from the four wheeler at every tree.  The unhooking of the bucket, the dumping of the sap into a larger 5 gallon bucket, the rehanging of the bucket, the replacing of the lid that has inevitably fallen into the snow at some point in the process.  The trudging through the snow to the next tree, the dumping of 2-3 trees’ worth of sap into the drum, the remounting of the four-wheeler.  Repeat.  Repeat.  Repeat for one hundred trees.

But we’ve seen the future, and the future is plastic.  Plastic tubing, to be exact.  With some assistance from good old fashioned gravity.  Most of our land is pretty flat, but we do have a nice slope on the southeast side that we’re using as a trial run for sap-collecting tubing.  Before the season started, we attached a length of one-inch diameter plastic tubing to a series of mature maples.  At the top of the slope, the tubing is attached higher on the tree, and by the bottom of the slope it’s only a couple feet off the ground.  A carpenter’s level assured us that we had a consistent downward slope of tubing with no level spots for sap to pool.  Then once it was time to tap the trees, instead of hanging a bucket from a metal spline on each tree along the slope, we used plastic taps.  The plastic taps have small tubes attached to them that splice into the main tubing, giving the sap a clear path out of the tree, down toward lower ground.  At the bottom of this sap water slide?  One of those beautiful blue 55 gallon drums, already partially full of clear, pure maple sap.